Tip and shank for hammer mills



P 4, 1951 c. E. ANDERSON 2,566,758

TIP AND SHANK FOR HAMMER MILLS Filed June 13, 1949 2 Sheets-Sheet 1 I N VENTOR Carlos EAndersom.

TTORNEY Sept? 1951 c. E. ANDERSON 2,566,758

TIP AND SHANK FOR HAMMER MILLS Filed June 15, 1949 2 Sheets-Sheet 2 INVENTOR Anderson.

A TORNEY Patented Sept. 4, 1951 TIP AND SHANK FOR HAMMER MILLS Carlos E. Anderson, Chicago, 111., assignor to Kensington Steel Company, Chicago, 111., a corporation of Illinois Application June 13, 1949, Serial No. 98,770

6 Claims. 1

This invention relates to rotary hammers, and more particularly to an improvement in a com- 'bined shank and renewable tip construction.

One of the objects of the present invention is to provide a hammer shank having a head including upper and lower transverse recesses which define an intermediate transverse rib, said recesses and rib having wedging surfaces medially interrupted by a keeper recess, and all of which recesses cooperate with mating parts of a renewable tip to securely hold the tip against vertical and sidewise movement when the tip and head of the shank are fastened together.

A further object is to provide a renewable tip that is readily replaced on the shank itself and which is simple and effective in construction and thereby lends itself readily to convenient manufacturing procedures.

With the above and other objects in view, which will more readily appear as the nature of the invention is better understood, the same consistsin the novel construction, combination, and arrangements of parts, hereinafter more fully described, illustrated and claimed.

A preferred and practical embodiment of the invention is shown in the drawings, wherein:

Figure l is an exploded perspective view of the preferred form of the invention with the tip turned 90 from its normal position;

Figure 2 is a side elevation, partly in section, of the hammer and tip of Figure l assembled;

Figure 3 is a horizontal cross section on the line 3-3 of Figure 2;

Figure 4 is a vertical cross section of a modified form of shank head and tip;

Figure 5 is a horizontal cross section of the construction shown in Figure 4;

Figure 6 is a detail perspective of the bolt end and nut of Figures 4 and 5;

Figure '7 is a side elevation partly in section of a hammer and tip used in primary crushing mills;

Figure 8 is a horizontal section taken on the line 8--8 of Figure 7.

Similar reference characters designate corresponding parts throughout th several figures of the drawings.

In all forms of the invention, th shank of the hammer is designated generally as 'A, and the tip is generally identified as B. The shank A is formed in one piece and the upper portion thereof is provided with an openingv I for mounting the shank on the shaft or pin of the rotor.

The lower portion or head of the shank A is provided with a special head formation intended to be complementary to the mating portion or inner face of the tip B. In all forms of the invention the mating or matching portions of the hammer and tip are the same, and such differences as may exist as between Figures 1 to l on one hand and Figures 5 and 6 on the other, reside in the holding means or bolts for removably conmeeting the tip to the hammer. In Figures 7 and 8, th same general matching or mating portions of the hammer and tip are employed except that in these latter figures, the construction is made heavier for primary mills, while in Figures 1 to 6, inclusive, the construction is of the type usually used in mills for fine crushing.

Referring to the head of the shank A, it will be observed that the front portion 2 is provided across its face with an upper recess or mortise C formed by the upper wall 3, substantially vertical wall 4, and a lower wall 5, the said Walls 3 and 5 flaring outwardly. The lower wall 5 of the upper recess is connected by a fillet with a substantially vertical wall 6, and the lower portion of the vertical wall 6 is connected by a fillet I of relatively large radius with an arcuate wall 8. This ar rangement provides a transverse rib D of substantial depth as compared with the vertical depth of the recess C. The arcuate wall or ledge 8 is joined by a fillet 9 with a vertical wall Ill which terminates at the lower end of the shank. 'As will be seen from Figure 1 in particular, the upper recess C overlies the horizontally extending subjacent rib D which in turn overlies the two-sided bottom recess E formed by the walls 8 and I0.

As will also be apparent from Figure l, the rib 6 is medially provided with a vertical keeper recess F formed by the side wall I I, bottom or inner wall I2, and side wall I3, the walls II and I3 tapering outwardly.

The tip B is provided with a flat front face I4 and an upper portion or flange I5 formed by the upper wall It and the bottom wall it connected by a transverse wall I8. Th walls I6 and I! are tapered to match the flaring relationship of the walls 3 and 5 of the upper recess C of the shank and the walls I 6 and I! of the tenon are less than the depth of the recess C so as to originally leave clearance between the vertical wall 4 of the shank and the vertical wall I8 of the tip to pro vide room for take-up due to wear. The medial portion of th renewable tip B is provided with a transverse recess G whose upper wall is formed by the wall I! of the tenon I8 andwhose bottom wall I9 is connected with a relatively lon curved wall 20 so that the said recess G snugly embraces portion of the transverse recess of the tip B is provided with a key K for fitting in the vertical recess F of the shank. That is to say, the medial portion of the transverse recess of the tip B is provided with a vertical key K formed by th side 7 wall 2 I, outer Wall 22, and side wall 23. The side walls 2| and 23 have a matching taper with relation to the walls It A3 of the medial recess It will thus be apparent that the;

of the shank. mating portions of the shank and tip described have a frictional or wedge fit so that the parts will be tight at the time of installation, and dur ing us under th assisting force of the fastening means presently to be described.

Before proceeding to a description of the fastening means, it is important to note that the tip B below the transverse recess G is formed with a bottom wear portion or flange 24 which includes the rear vertical wall 25 adapted to abut wall It and lower impact face 26. Thus, the tip has right angularly disposed impact or wear faces M and 25, and the face It is normally in the same plane as the short face 2 of the head of the shank while the impact face 26 is normally below the lowest point of the head of the hammer shank A. It may also be pointed out that the wall 1---% of the shank is designed to follow the line of wear of the hammer, based on a worn solid hammer as gained from previous experience, so that as the front and bottom impact faces of the tip wear, the wear may take place to a maximum extent, that is, until wear approaches the ledge or wall 2B of the tip.

From the foregoing it will now be seen that the tip A is of substantially channel shape crosssection with the recess G forming a channel or trough bounded by the upper and lower flange elements and 24.

Referring now to the means for holding the tip to the shank, it will be observed that the front face I4 of the tip B is preferably provided with a socket 2i communicating with an opening 28 through the key K of the tip, which opening in turn aligns with an opening 29 in the vertical recess F of the shank, and which opening extends to the rear face of the shank to communicate with a countersunk recess 30. The

V countersunk recess 21 at the impact face of the tip is intended to non-rotatably receive the head of a bolt 3!, the said bolt passing through the aligned openings 28 and 29 to receive a nut 32 located in the rear countersunk recess 30. It will thus be seen that the opposite ends of the bolt lie in countersunk recesses so that at no time are they exposed to direct blows or impact. Also, the front recess or cavity 27! which receives the head of the bolt will soon become filled with fine debris and thus protect the head of the bolt from continued wear or abrasion.

When the bolt 3| is tightened up, it will, of course, be understood that the tip B will be wedged against the mating parts of the shank and that the tip will therefore always be held against vertical movement due to the interfitting of the related parts of the hammer and tip. The

bolt 31 merely locks the tip to the shank while the recess E of the shank and the interfitting key K of the tip will absorb all lateral forces imposed on the tip and distributethem over the end of the shank. In other words, the key and nection with Figures 1-3. However, in this form of the invention, the fastening means is different in the respect that there is no opening at the front face M of the tip. In this arrangement the key K of the tip is provided with a socket or cavity 33 to receive an internally threaded non-circular bushing or nut 34 which is wedged in the socket and receives the threaded end of a bolt 35 applied through mating openings in the shank and the tip so that its head 36 is accessible through the recess 31 countersunk in the rear face of the shank.

Figures '7- and 8 illustrate the same arrangement of mating parts on the shank and the tip except that two keys K. and K and corresponding keeper recesses are provided due to the heavy duty to which a tip of this type is subjected. Also, two fastening bolts 36 and 3'! areassembled in the same fashion as described in connection with Figure 1 except that it will be understood that the front face 14" of the tip shown in Figures 6 and 7 is provided with two countersunk openings 2'! and, the rear face is provided with elongated recesses 30* whose outer ends open at the sides of the shank head for convenient access to the nuts on the bolts 35 and 37.

From the foregoing, it will be understood that the principal features of the invention are the mating configurations of the one-piece shank and the one-piece tip held together by appropriate fastening means. Figures 4 and 5, and Figures 7 and 8 illustrate the range of possible modification within the scope of the improved mating or interlocking features of both the shank and the tip.

When one of the tips B in any form of the invention becomes worn, it is believed to be apparent that it is unnecessary to remove the shank A from the rotor in order to renew the tip. In other words, it is simply necessary to remove the fastenings holding the tip B to the shank A and substitute a fresh unworn tip. Due to the fact that the tip protects all of the mating sur faces of the shank, the latter are subjected to little or no wear and the new tip will readily seat in the complemental portions of the old shank.

Without further description it is thought that the features and advantages will be readily apparent to those skilled in the art, and it will, of course, be understood that changes in the form, proportion and minor details of construction may be resorted to, without departing from the spirit of the invention and scope of the appended claims.

I claim:

1. A hammer for rotary crushing mills, comprising, a shank having a head provided with a front face and formed below its front face with an inset transverse upper recess, a subjacent transverse rib overlying a two-sided bottom recess,'said ribhaving a medial keeper recess therein; a removable tip having angularly disposed front and bottom impact faces and provided at its inner side with a medial transverse recess for embracing the rib, a key in the lastinentioned recess for fitting in the said keeper recess of the rib, said transverse recess in the tip being bounded by upper and lower flanges having wedging engagement respectively within the upper and lower recesses of the shank head, and bolt and nut means for fastening the head and tip together.

2. A hammer according to claim 1 wherein, the front impact face of the tip and the rear face of th shank are provided with countersunk portions and communicating openings to receive a bolt whose head is shielded within one of the openings and whose clamping nut is shielded in the other of said openings.

3. A hammer for rotary crushing mills according to claim 1, wherein, the key is provided with with a threaded socket registering with an opening in the shank head and the rear face of the shank head is provided with a countersunk recess, and a bolt threaded at one end and adapted to enter said opening and said threaded socket and having its head disposed in said countersunk recess.

4. A hammer for rotary crushing mills according to claim 1, wherein, the rib on the head is provided with a plurality of spaced keeper recesses and the transverse recess at the inner side of the rib is provided with a plurality of spaced mating keys, and a plurality of fastening elements holding the shank-head and tip at the location of said keys and their mating keeper recesses.

5. A hammer for rotary crushing mills, comprising, a shank having a head provided with a front face and formed below its front face with an inset transverse upper recess, a subiacent transverse rib overlying a two-sided bottom recess, said rib having a medial keeper recess therein; a removable tip having right angularly disposed front and bottom impact faces and provided at its inner side with a medial transverse recess for embracing the rib, a key in the lastmentioned recess for fitting in the said keeper recess of the rib, said transverse recess in the tip being bounded by upper and lower flanges having wedging engagement respectively within the upper and lower recesses of the shank head, a non-circular internally threaded nut in the rear face of the key on the tip, and a fastening having a head at one end and threaded at the other, said fastening passing through the shank head and having its threaded end engaging the internally threaded nut.

6. In a hammer composed of a shank and a renewable tip for use in hammer mills, wherein the lower portion of the shank has a transverse rib and :a recess with outwardly flared upper and lower planar walls, a second recess below said rib having an arcuate wall curved in the direction of said lower planar wall of the first recess and a continuous terminal transverse wall connected to said arcuate wall by a fillet, the shank and tip having complementary mating surfaces held together by a fastener extending through said tip and shank and exposed at each end for ready access to either end of said fastener, said tip being provided at its inner side with upper and lower flanges, said upper flange having upper and lower planar bearing surfaces conected by a, rear vertical planar surface, said upper and lower planar bearing surfaces being tapered in the direction of said rear vertical planar surface, said lower flange projecting rearwardly substantially twice the extent of said upper flange over only a fractional part of the lower portion of the shank to said terminal transverse wall, the Vertical rear wall of said lower flange being parallel to the wear face of the tip and forming a continuous transverse wall abutting said terminal transverse wall across the lower portion of the shank, said lower flange of the tip having an upper curved bearing surface, said tip flanges and their said respective bearing surfaces forming a transverse recess, and a projecting locking key formed with a countersunk socket for non-rotatably receiving the head of said fastener, said key being integral with the tip, the outermost projecting face of the key being substantially coplanar with the said rear vertical planar surface of the upper flange, said key lying medially in the recess between said upper and lower flanges of the tip for reception in the recess in the transverse shank rib to hold the vertical rear wall of the lower flange in cooperative abutment with said continuous transverse terminal wall across the lower portion of the shank when the fastener is in position to prevent lateral movement and shearing stresses on said fastener, said key and lower portion of the shank being shielded by said lower flange against wear.

CARLOS E. ANDERSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,016,979 Williams Feb. 13, 1912 1,166,698 Lincoln Jan. 4, 1916 1,456,987 Lucas May 29, 1923 1,538,831 Lucas May 19, 1925 1,693,058 Shelton Nov. 27, 1928 1,724,786 Van Buskirk Aug. 13, 1929 2,152,332 Smith Mar. 28, 1939 2,467,865 Smith Apr. 19, 1949 FOREIGN PATENTS .Number Country Date 86,773 Sweden May 7, 1936 475,430 Great Britain Nov. 19, 1937 498,415 Great Britain Jan. 9, 1939 584,878 Great Britain Jan. 24, 1947 

